Ludwig rissmtjller



LUDW'IG RISSMULLER, OF NEWARK, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE GENERAL AMERICAN REDUCTION COMPANY, OF

NEW YORK, N. Y.

PROCESS OF TREATING GARBAGE AND FERTILIZERS OBTAINED THEREFROM.

SPECIFICATION forming part of Letters Patent No. 611,580, dated September 27, 1898.

Application filed October 20, 1896. Serial No. 609,410. (No specimens.)

T0 aZZ whom) it may concern.-

Be it known that I, LUDWIG RISSMULLER, a citizen-of Prussia, and a resident of Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in the Treatment of Garbage, of which the following is a specification.

The object of myinvention is to economically and expeditiously treat garbage, slaughter-house refuse, animal or vegetable Waste matter, &c., for the purpose of separating the grease therefrom and for the purpose of converting the heavier substances into fertilizing material practically freed from grease.

I-Ieretofore in the treatment of garbage for the purpose of extracting the grease therefrom and for the conversion of the residuum into fertilizing material, 860., so far as I am aware, operators have not succeeded in extracting from the garbage a sufficient proportion of the grease as that the residuum could be fairly said to be freed from grease, except with naphtha, which is disadvantageous, the usual proportion of grease remaining in said residuum being about fifty per cent. of the amount contained in the garbage before treatment. Consequently all efiorts to produce a fertilizer which was practically freed from grease (a result long desired) have failed, and the great proportion ofgrease remaining in the fertilizer is not only lost to commerce, but reduces the Value of the fertilizer, as it delays its action. True it has sometimes been the practice to incinerate the residuum, but this has resulted in destroying the grease and has left the phos phoric acid of the original garbage and a part of the potash in an insoluble form. It has been proposed to burn all of the grease out of the residuum; but by this method the grease is entirely lost to commerce, and such a degree of heat is necessary that the ammonia will be entirely liberated and driven off from the ashes. 7

It has been found that when garbage has been boiled with water or acids (or both) only a portion of the grease rises to the surface, the rest remaining as an emulsion in the mass. The garbage which has been boiled with water has heretofore been treated in power-presses to remove a solution containing water and grease, which was allowed to remain in settling-tanks; but this treatment in presses has seldom resulted in removing more than half the grease from the garbage. The residuum containing such a large proportion of grease is dried and after grinding is used as fertilizing material.

When acids have been used (alone or with of material'to be treated. The garbage should be subjected to the action of the acid in a lead-lined vessel like the pulp-digesters in common use. The garbage, acids, and water are boiled until converted into a uniform mass, not unlike a thick heavy soup, in which the original structure of the garbage material has been destroyed and the grease contained in the form of an emulsion. This results in bringing the garbage to a stage which permits the instant and complete removal of the grease, unmixed with other substances, from the mass. By my process after such conversion the mass is led into a centrifugal separator of high speed. The centrifugal separator which I have used is one having a non-perforated bowl, and I have found that the ordinary centrifugal separators having perforated bowls cannot be used to separate the ingredients of a mass according to their respective specific gravities, but can only be used as driers or presses. Hence centrifugal separators which act merely to expel water 5 are not available in my process. In the optoo I know, be accomplished by any other means because of the thickness of matter acted upon. Generally speaking, the mass will be separated into three substan cesfirst', the heavier solids; second, the acid solution, containing also the soluble substances which were in the garbage, and, third, the greases rendered out of the garbage. The solids being the heaviest will be driven to the wall of the separator, the acid solution will be the next layer, and nearest the center will be the greases. The rotary movements of the bowl are also utilized for driving the separated grease out of the mass, the solution and heavier ingredients being removed together. The grease may then be used for any purpose desired. The solution and solids are then worked into fertilizing material. The mixture is treated with phosphate of lime or other suitable substances acting to neutralize or remove the free acids, the presence of which render drying difficult.

By the presence during the conversion of the garbage of free acidssulfuric, phosphoric, or muriatic acidthe phosphoric acid of the tribasic phosphate of lime (rock phosphate, &c.) will be formed in the soluble or available form and the potash as soluble potash, as by the treatment of the garbage with either sulfuric 0r phosphoric acid the phosphoric acid which was contained in thegarbage before conversion is freed therefrom during treatment by my process and can stand the high temperature required. I11 addition the potash, which was presentin the form of insoluble silicate, is by the presence of the free phosphoric acid transformed into a sol uble salt.

In view of the fact that the heavier ingredients rejected by the closed-bowl centrifugal separators are practically free of grease it is not necessary in drying to employ a degree of heat which will deleteriously affect the ammonia.

The product can be more advantageously used for fertilizing than fertilizing material produced from garbage by other processes in view of the fact that it is practically freed from grease, (which is objectionable in that it delays theaction of the fertilizer.)

I am aware that it has been proposed to use a perforated-bowl centrifugal separator for pressing the liquids out of a mass of garbage which has been pulped and compressed, (as in United States Patent No. 506,361 to Dowling;) but in this connect-ion I call particular attention to the fact that the perforated-bowl centrifugal separator there shown is not used or useful for separating the ingredients of a mass according to the respective specific gravities of the ingredients, but merely dries the garbage, the liquid ingredients driven off also containing dirt, sticks, and other solid substances expelled through the perforations of the bowl. In addition the operations of pulping and compressing proposed by Dowling do not result in the eX- pulsion of an appreciable proportion of the greases, nor does pulping convert the garbage into a uniform fluid mass in which the greases are contained as an emulsion.

I am also aware of the United States Patent No. 530,126 to Powter for process of utilizing garbage and similar waste products and desire to be understood as disclaiming the process therein described and claimed. In the said Powter process the floating grease is removed from the sludge by skimming. This removed grease, however, contains acids,

dirt,and light ingredients,necessitating a fur-.

ther treatment for their removal. The garbage remaining in the digester after skimming still contains seventy per cent. (approximately) of the grease originally contained in the garbage, and this grease cannot be removed except by employing such ahigh degree of heat as would liberate the ammonia from the ashes.

WVhat I claim is 1. The process of treating garbage, consisting in, first, boiling the garbage until it is converted into a uniform fluid mass, in which the structure of the garbage has been destroyed and the greases rendered therefrom, and,second, separating the ingredients of said mass by centrifugal action according to their respective specific gravities, and removing substantially all of the greases from the mass.

2. The process of treating garbage, consisting in boiling the garbage with acid until converted into a uniform fluid mass in which the structure of the garbage has been destroyed and the greases rendered therefrom, and, second, separating the ingredients of said mass by centrifugal action according to their respective specific gravities, and removing substantially all of the greases from the mass.

3. The new grease-freed fertilizer, having available ammonia and resulting from the subjection of waste matters to the herein-dcscribed process, substantially as described.

In witness whereof I have hereunto signed my name this 15th day of October, 1896.

LUDWIG RISSMULLER.

In presence of WM. 11. BERRIGAN, J r., JAMES J. OoscRovE. 

